In his hugely influential treatise The Omnivoreâ€™s Dilemma , Pollan traced a direct line between the industrialization of our food supply and the degradation of the environment. His new book takes up where the previous work left off. Examining the question of what to eat from the perspective of health, this powerfully argued, thoroughly researched and elegant manifesto cuts straight to the chase with a maxim that is deceptively simple: â€œEat food, not too much, mostly plants.â€ But as Pollan explains, â€œfoodâ€ in a country that is driven by â€œa thirty-two billion-dollar marketing machineâ€ is both a loaded term and, in its purest sense, a holy grail. The first section of his three-part essay refutes the authority of the diet bullies, pointing up the confluence of interests among manufacturers of processed foods, marketers and nutritional scientistsâ€”a cabal whose nutritional advice has given rise to â€œa notably unhealthy preoccupation with nutrition and diet and the idea of eating healthily.â€ The second portion vivisects the Western diet, questioning, among other sacred cows, the idea that dietary fat leads to chronic illness. A writer of great subtlety, Pollan doesnâ€™t preach to the choir; in fact, rarely does he preach at all, preferring to lets the facts speak for themselves. (Jan.)